The invention relates to memory packs used in an electronic cash register.
Recently, a number of cash registers are used in supermarkets, department stores, etc. The electronic cash register comprises a read only memory (ROM) storing a program and a random access memory (RAM) for storing the information to possibly be changed such as tax information and price look-up information. By convention, in order to change the information stored in the RAM, electronic cash registers ae used to individually write new information into the RAM. Since such an operation is troublesome and takes much time, a plurality of memory packs with a memory region corresponding to the memory region for storing the changeable information of the RAM, are used and the changeable information are commonly loaded into these memory packs by a store data processing apparatus. These memory packs are inserted into receptacles of the electronic cash registers. With such an arrangement, the information in the RAM may easily be changed.
However, the conventinal electronic cash register is not provided with a suitable means for checking whether this kind of memory pack is surely coupled with the cash register or not. Accordingly, proper information may fail to be loaded into the memory pack.